Three-pion production on complex nuclei at 23 GeV/c

Abstract

The production of three pions has been examined in interactions of 23-GeV/c ${\ensuremath{\pi}}^{\ensuremath{-}}$ with complex nuclei. A partial-wave analysis of the three-pion system has been performed showing that the spin-parity structure is very similar to the one produced in hydrogen. The production cross section for various nuclei have been compared with an optical-model calculation. In the ${A}_{1}$ region the absorption cross sections obtained from the model are 25 mb for ${J}^{P}={1}^{+} \mathrm{and} 60$ mb for ${J}^{P}={0}^{\ensuremath{-}}$.